The present invention relates to a closure, and more particularly a closure having one straight surface and one curved surface forming the top cover of the closure, or two curved surfaces forming the top cover of the closure.
Packaging containers are secured by closures in a wide variety of manufacturing applications. In the manufacturing industry many different products are filled into containers and securely sealed through the use of packaging machines. These packaging line machines work more quickly and efficiently when containers and closures can smoothly be maneuvered from one position to another through the manufacturing line until a final filled container is securely sealed.
Many advantages have been made through the years creating a manufacturing environment where packaging machines can efficiently and rapidly move closures from one area to another, until the container is filled and secured. In an effort to maintain a high packaging line speed, mechanisms have been developed for, picking a closure from a bulk supply, and transporting it to its final position onto the packaging reservoir. Although these applicators have lead to a more efficient production, if problems such as disorientation of the closure, or the breaking or bending of the closure occur during the packaging line process, it causes, in effect devastation to the efficiency of the entire production line. As such, it is critical to production to prevent against failure on the packaging line.
Some of the more typical problems associated with the packaging line are the result of closures becoming disoriented when moved from one area to another. When the closure is transferred from the bulk supply to a convey or belt, it is imperative that the orientation of the closure be top cover side up, as this facilitates the ease of the applicator to move the closure from the convey or belt onto the container. Subsequently, if the closure is not correctly placed over the container the entire packaging line is halted. In a typical closure, the top surface can have a depression or convex curve or a concave bulge caused by the molding process or by the pulling of gravity when sitting and cooling down after molding. It is generally the case, that when a plastic closure is removed and pushed away from its respective mold a depression may be caused in the top surface of the closure. In addition, the closure generally shrinks as it cools, causing warping of the top surface. Such an indentation or depression causes the closure to occasionally fall onto the convey or belt before being placed over the container, with its top surface or cover, face down and the skirt of the closure face up. Thus, excessive convex or concave deformation to the surface of the closure can cause flipping of the closure during the capping process, and such misorientation of the closure can cause havoc in the capping process. When this occurs the closure will be picked up, top down and wrongly placed over the container resulting in the failure and halting of the entire packaging line.
Moreover, the ability of a closure to withstand the manipulation and transport during manufacturing is facilitated by the strength of the top of the closure itself and its ability to prevent the sidewalls of the closure from collapsing inward. To ensure strength, most closures are made with a more durable material, and have thicker plastic tops, which in turn prevents against breaking and bending, and thus the closure is better able to withstand the packaging line process. The drawback with manufacturing closures with stronger, thicker materials is that it becomes more expensive to manufacture, in addition the closures are typically less flexible and manageable in the processing line. Therefore, there exists a need for a durable, stronger and relatively inexpensive closure that can be easily maneuvered through the high speed packaging line process and secured over containers without the closures warping.
Additionally, there exists a need for a closure, which eliminates the inward dome shaped top surface and specifically calls for a closure having a flat or straight top, which will prevent disorientation during the packaging process, by having the closure uniformly positionable top down on the packaging line and over the container. Another advantage for a closure having a flat or straight top surface or cover is that its appearance is much more aesthetically pleasing, as opposed to a closure having a sunken or depressed top surface.